Improvement in variable cut-offs for steam-engines



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AWILLIAlilB. CROSS, OF SACRAMENTO, CALIFORNIA.

Letters Patent No. 111,180, dated January 24, 1871.

IMPROVEMENT IN VARIABLE CUT-OFFS FOR STEAM-ENGINES.

The Schedule referred to in these Letters Patent and making part of lthe same.

To all whom it may concern Be it rknown that I, WILLIAM B. Unoss, of Sacramento, in the county of Sacramento and State of Oalifornia, have invented a new and improved Variable Out-otifor Steam-Engines; and I do hereby declare that the following is a full, clear, and exact descrip tien thereof, which will enable others skilled inthe art to make and use the same, reference being had to the accompanying drawing.;` forming part of this speci-y iication.

This invention relates to improvements in variable cut-od' apparatus forsteam-engines, and consists in a combination, with a vibrating lever connected with the valve-stem, so as toopenthe valve when moved in one direction, of an adj ust-able inclined sliding block,

arranged between the lever and` point of the valve- Stem, to which motion is communicated by the said lever, and connected with an eccentric, or any other moving part, so as to be caused toV slide on the lever and let the valve close sooner than it would i1" moved back with the lever, said block beiugarranged so that it may be shifted while in motion to vary the point of cutting ofi'.

The invention also comprises an arrangement of operating and adjusting devices for' the said block, the said apparat-us being adapted for working two valves alternately, one at each end of the engine.

Figure l is a side elevation, partly sectioned, of my improved valve-gear applied to two valves, which may be supposed to be arranged one at each end of 4the cylinder;

Figure 2 is a section on the line a; x; and

Figure 3 is a section on the line y yl Similar letters of reference indicate corresponding parts.

A A represent two valve-chests, one at each end oi' the steam-pipe 13.

O represents the valve-stems, which, in this inv stance, are arranged vertically.

They have each a long slot or mortise in the upper end, through which a lever, D, passes, said levers'be` ing pivoted to any suitable support at E, and having their ii-ee ends extending toward, but terminating short of, each other over a rock-shaft, F, carrying the toes G, and worked by the eccentric or other moving part, to which it is connected bythe rod H, thc said toes alternatelyiaising.each lever to open the valves.

The valve-stems have cross-heads, I, working on lthe guide-rods K, and on which cross-heads the coiled springs L work to close the valves.

The mortises in the upper ends of theR-alve-stems are considerably longer than the width of the levers, to admit of independent movement of the said stems, also to admit of the reception of the sliding block M between the upper sides of the levers and the walls at the upper ends ofthe mortises.

These blocks are fitted to the upper sides of the said levers so asv to slide back and forth on them, and they have the inclined planes N upon their upper sides. l

They are connected by the rods O to the -neaded lever P, pivoted at Q to an arm, R, rising up from, and turning freely on, the rock-shaft F, which arm is connected by a rod, R', with an eccentric or other properly-moving part ofthe engine. l

The free end ot' lever P is connected by a rod, S, to a bar, T, by hooking into a hole in it, ofwhich there area number, for shifting the rod from one to the other for varying the lever I up or down, to shift ,the arms'U of' the head forward or backward to change the slides on the levers.

For reducing the friction as much as possible, a friction-roller, V, is placed inthe slot of each valvestem, above the sliding block M, for the latter to work under.

' 'lhe arm It is caused to move forward and backward in such relation to the movements of the rock-shaft and toes G that, previous to the rising of lever D, the slidelM will be drawn forward under the roller, so that the rising of the said lever will raise the valve, and previous to the downward movement of the lever the `slide will be moved back, the inclined plane N passing from under the roller and letting the valve be suddenly closed by the springs. This closing movement is made sooner or later, according to the position of the F-lever and the slides Mon the levers D, as will be clearly understood by inspection of 'the drawing.

It is not necessary that the levers D pass through slots in the valve-stem, as they may work along side of the stems, andthe frictio1`1rollersmay be supported onstu'ds p rojecting from the said'stems.

Having'th'us described my invention,

I claim 4as newA and desire to secure bv Letters Patent- 1. The levertbr working the valve-stem, combined as described with the sliding block having the inclinedv plane, as and for the purpose specified.

2. The combination, with the sliding block M, of `the rod O, lever l?, adjustable rod or hook S, and'arm lt, all substantially as specified.

3. IThe combination, `with the rockshai^`t, toes, and levers D, of the arnrR, lever l?, adj listing-'rod or hook S, rod O, slide M, and'valve-stem C, all substantially as specified.V v

Witnesses: VILLIAM B. GROSS.

HENRY C. J oHNso'N, JOSEPH GROGHAN. 

